Documentation/features/locking: update lists

The locking feature lists don't match reality as of v5.3-rc1:

* arm64 moved to queued spinlocks in commit:
  c1109047
  ("arm64: locking: Replace ticket lock implementation with qspinlock")

* xtensa moved to queued spinlocks and rwlocks in commit:
  579afe86
  ("xtensa: use generic spinlock/rwlock implementation")

* architecture-specific rwsem support was removed in commit:
  46ad0840
  ("locking/rwsem: Remove arch specific rwsem files")

So update the feature lists accordingly, and remove the now redundant
rwsem-optimized list.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/features/locking/queued-rwlocks/arch-support.txt

@@ -30,5 +30,5 @@
     |          um: | TODO |
     |   unicore32: | TODO |
     |         x86: |  ok  |
-    |      xtensa: | TODO |
+    |      xtensa: |  ok  |
     -----------------------

Documentation/features/locking/queued-spinlocks/arch-support.txt

@@ -9,7 +9,7 @@
     |       alpha: | TODO |
     |         arc: | TODO |
     |         arm: | TODO |
-    |       arm64: | TODO |
+    |       arm64: |  ok  |
     |         c6x: | TODO |
     |        csky: | TODO |
     |       h8300: | TODO |
@@ -30,5 +30,5 @@
     |          um: | TODO |
     |   unicore32: | TODO |
     |         x86: |  ok  |
-    |      xtensa: | TODO |
+    |      xtensa: |  ok  |
     -----------------------

Documentation/features/locking/rwsem-optimized/arch-support.txt

-#
-# Feature name:          rwsem-optimized
-#         Kconfig:       !RWSEM_GENERIC_SPINLOCK
-#         description:   arch provides optimized rwsem APIs
-#
-    -----------------------
-    |         arch |status|
-    -----------------------
-    |       alpha: |  ok  |
-    |         arc: | TODO |
-    |         arm: |  ok  |
-    |       arm64: |  ok  |
-    |         c6x: | TODO |
-    |        csky: | TODO |
-    |       h8300: | TODO |
-    |     hexagon: | TODO |
-    |        ia64: |  ok  |
-    |        m68k: | TODO |
-    |  microblaze: | TODO |
-    |        mips: | TODO |
-    |       nds32: | TODO |
-    |       nios2: | TODO |
-    |    openrisc: | TODO |
-    |      parisc: | TODO |
-    |     powerpc: | TODO |
-    |       riscv: | TODO |
-    |        s390: |  ok  |
-    |          sh: |  ok  |
-    |       sparc: |  ok  |
-    |          um: |  ok  |
-    |   unicore32: | TODO |
-    |         x86: |  ok  |
-    |      xtensa: |  ok  |
-    -----------------------